20219689 has 4 divisors (see below), whose sum is σ = 23108224. Its totient is φ = 17331156.

The previous prime is 20219687. The next prime is 20219701. The reversal of 20219689 is 98691202.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98691202 = 2 ⋅49345601.

It is a cyclic number.

It is not a de Polignac number, because 20219689 - 2¹ = 20219687 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20219687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1444257 + ... + 1444270.

It is an arithmetic number, because the mean of its divisors is an integer number (5777056).

Almost surely, 2^20219689 is an apocalyptic number.

It is an amenable number.

20219689 is a deficient number, since it is larger than the sum of its proper divisors (2888535).

20219689 is an equidigital number, since it uses as much as digits as its factorization.

20219689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2888534.

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 20219689 is about 4496.6308498697. The cubic root of 20219689 is about 272.4320241186.

It can be divided in two parts, 202 and 19689, that added together give a palindrome (19891).

The spelling of 20219689 in words is "twenty million, two hundred nineteen thousand, six hundred eighty-nine".